Apparatus for production of oxygen and nitrogen



Oct. 28 1924. 1,513,116

J. G. LAFFE'RTY APPARATUS FOR PRODUCTION OF OXYGEN AND NITROGEN Original Filed March 22. 1919 FIG. 1

Patented Oct. 28, 1924.

UNITED STATES JAMES G. LAFFERTY, 01-. CO'RAOPOLIS, PENNSYLVANIA.

f APPARATUS FOR PRODUCTION OF OXYGEN AND NITROGEN.

Application filed March 22, 1919, Serial No. 284,308. Renewed March 30, 1923.

To all whom it may concern:

Be it known that I, JAMEs G. LAFFERTY', a citizen of the United States, and resident of Coraopolis, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Apparatus for Production of Oxygen and Nitrogen; and I do hereby declare the following to be a full, clear. and exact description thereof.

My invention relates to apparatus for the production of pure oxygen, nitrogen and argon.

The object of my invention is to provide a simple and efficient form of apparatus by means of which air may be separated into its above constituent elements by first liquefying.

In the accompanying drawing, Fig. 1 shows a sectional elevation of my improved apparatus, and Fig. 2 is an enlarged sectional view of the condenser forming part of said apparatus.

In the drawing, the numeral 2 designates the air entrance pipe by means of which air, preferably dehydrated, is admitted to the apparatus. A valve 3 controls this supply of air to the apparatus. The air passes to the compressor 4 which is of an ordinary type, and the compressed air is then forced through the pipe 5 into the coil 6 located in the annular cooling chamber 7. A pipe 8 leads from the bottom of the coil 6 and said pipe passes into the coil 9 in the annular cooling chamber 10. A pipe 11 leads from the lower end of the coil 9 and said pipe connects with the coil 12 in the lower compartment 13 of the separating chamber 14. A pipe 15 leads from the coil 12 passing through the wall of the compartment 13 down where it enters the lower compartment 16 of the lower separating chamber 17, where it is connected to the coil 18 in said compartment 16. A pipe 19 connects with the coil 18, and said pipe passes out throughan opening in the compartment 16 and thence up to a point where it enters the liquid-receiving chamber 20, into which it discharges. This pipe is pro vided with the valve 21.

A pipe 22 is connected to the lower end of the liquid-receiving chamber and said pipe connects up to the end of the condensing chamber 23. This condensing chamber 23has at the lower end the spraying section 24 which is located in the upper compartment 25 of the separating chamber 14, C

tained within the condensing chamber 23 are the baflles 26 which retard the downward flow of the liquid.

In the present construction there are two separating chambers 14 and 17, and these chambers are connected in the following manner :An outlet 27 at the lower end of the compartment 13 is controlled by the valve 28 and said outlet is thus connected up to the upper end of the condensing chamber 29. This condensing chamber has the tubes 30 connected up with headers 31 and 32 for the passage of the liquid from one separating chamber to the other.

A pipe 33 connects with the condensing chamber 29, and said pipe passes up and into the annular cooling chamber 10, where it is connected with the coil 34. A pipe 35 is connected with the upper end of the coil 34 and said pipe is connected with the argon tanlr 36. valve 37.

The spraying device 38 is located below the condenser 29 said spraying device being located in the upper compartment 40 of the separating chamber 17.

A suitable compressor 41 is provided for compressing the air admitted from the atmosphere by the pipe 39, said air being previously dehydated as before and delivered to the pipe 42, a suitable valve 43 being provided for controlling the air supply.

The pipe 42 passes into the cooling cham her 7 and is connected to the upper end of the coil 42*. A pipe 44 is connected to the lower end of the coil 42, and said pipe passes into the cooling chamber 10 and is connected to the upper end of the coil 45 contained within said chamber. A pipe 46 is connected with the lower end of the coil 45, and passes out through the lower end of the chamber 10, and into the compartment 13 of the upper separating chamber 14, where it is connected with the upper end of the coil 46 contained within said compartment. A pipe 47 connected with-the lower end of the coil 46 passes down into the compartment 16 of the lower separating chamber 17, where it is connected with the coil 47 contained within said compartment. A pipe 48 is connected with the coil 47 and said pipe passes up and discharges into the liquid-receiving chamber 49, said pipe being provided with the valve 50.

i A p pe 51 l ads fro he lower end of the This pipe is provided with a receiving chamber 49, said pi e entering the condensing chamber 23, sai pipe having the spray nozzle 52 at the discharge end.

Leading from the upper end of the receiving chamber is the pipe 53 which. connects with the lower end of the cooling chamber 7. A pipe 54 leads from the upper end of the cooling chamber 7, said pipe having at its lower end the T-section 55, one branch of which; 56, leads to. the atmosphere, the other branch 57 to the nitrogen tank 58. These branches are provided with the valves 59 and 69 respectively. Pipes 61 connect the lower end of the compartment 16 of the separating chamber 17 with the evaporators 62 and 63. Coils 64 and 65 are located in the evaporating chambers. Pipes 66 and 67 connect to the upper endsof the evaporating chambers 62 and 63 respectively, said pipes uniting at 68 and passing by the pipe 69 into the coil 70 in the cooling chamber 10. A pipe 71 is connected with the coil 70 and said pipe passes down into the oxygen tanic 72. A valve 73 is provided in the pipe 71.

A suitable compressor 74 is supplied with air b the pipe 75. The air when compressed is delivered to the pipe 76 provided with a valve 77. The pipe 76 connects with the coil 76 in the cooling chamber 10, and a pipe 78 connects with the other end of said coil and with the coil 79 in the cooling chamher 80. A pipe 81 is connected with the coil 79, and said pipe connects up to the coils 64 aiid in the evaporator-s 62 and 63. The

pipes 82 and 83 are connected to the coils 65 and 64 respectively and are provided with the valves 85 and 86. The pipes 82 and 83 cohnect with the pipe,87, which leads to and discharges into the liquid-receiving cham- Ber '49. V y

A ipe 88 leads from the upper end of the liqui -re'c'eiving chamber 49, said pipe passing downand connecting with the cooling chambcr 80.

pipe 89 connects with the chamber 80 and enters the upper separating chamber and discharges into the passage 90 connectiiigthe upper and lower compartments of said separating chamber 14.

Pipes 91 and 91 lead from the upper compartment 25 of the upper separating chamber '14 into the cooling chamber 10. A pipe 92 is connected to the upper end of the coolihgchaniber 10. The more volatile gases arising in the separating -hamber 14 pass by the pipes 91 and 91' into the cooling chamber 10, and said gas is discharged from said cooling chamber by the pipe 92 and may be directed to the atmosphere by the pipe 93 provided with a valve 94. Pipe '92 is pro vidcd with the valve 95, so that in case it is ript desired 'to discharge these gases into the atmosphere they may be directed into the inlet .pipe to the compressor 4.

A "pipe '96 is connected to the upper end of the liquid-receiving chamber 20, said pipe being connected to the pipe 2, a valve 97 be ing provided in said pipe.

In describing the operation of the above apparatus, it will be necessary first to describe how the apparatus is first started in. order to bring the results desired.

7 In commencing operations, air, preferably dehydrated, is introduced by the ipe 2, the valves 94 and 95 being closed an the valve 3 open. This permits the air to enter the compressor 4, and the air compressed therein is forced through the pipe 5 into the coil 6 of the cooling chamber 7. This air in its passage through this coil is reduced in temperature by the gases contained within the chamber 7 and surrounding said coil. These cooling gases, as will hereinafter more fully appear, are the more volatile gases which escape from the liquid-receivinv chamber 20, and discharge to the atmosphere throu 11 pipe 56 until the necessary liquid is f veloped to start the apparatus. The air cooled in this manner is delivered by the pipe 8 to the coil 9 in the cooling chamber 10, also cooled by gases hereafter admitted by the pipes 91 and 91? from the separating chamber 14. In this way the tem erature of the air is further reduced and it nally passes from the coil 9 by the pipe 11 to the coil 12 within the lower compartment 13 of the separating chamber 14. The gas then passes from this coil by the pipe 15 to the coil 18 in the lower compartment 16 of the lower separating chamber 17. The gas passes out by the pipe 19 and, being conducted upwardly, is discharged into the liquid-receiving chamber 20. WVhen the liquid in the chamber 20 has reached thepoint where it will overflow by the pipe 22 into the condenser 23, the liquid passes down through said condenser and out through the spraying device 24, and thence down through the passage 90 into the lower compartment 13 of the separating chamber 14. The liquid collects in this compartment until there is sufiicient to insure the cooling of the gases in the coils contained within said compartment. The valve 28 is then opened and the liquid allowed to pass down through the condenser 29 into the sprayer 38, whence it is discharged into the lower separating chamber, passing down into the lower compartment 16 thereof. When the liquid has attained the proper height in the compartment 16, it pass es by the pipes 61 into the evaporating chambers 62 and 63. The evaporation takes. place in these chambers due to the heat given up by the coils 64 and 65, and the gases pass up through the pipes 66 and 67, and uniting at 68, pass by the pipe, 69 to the coil in the cooling chamber 10. From the coils70 the gases pass by the pipe 71 down to be discharged to the atmosphere bythe pipe 109, the valve 101 being opened and the valve 73 closed. This operation is continued until the tests show that pure oxygen is being discharged from the branch pipe 100. The machine up to this point has been operated merely to secure the necessary liquid air and temperature for the separation and production of the gases which constitute said liquid.

I will first describe the apparatus in connection with the production of pure oxygen and pure argon. In this case the liquefied air in the receiving chamber 20 passes down through the condenser 2-3 and is discharged by the spray 2 1 into the upper compartment 25 in the separating chamber 14. Here it is met by the volatile gases rich in nitrogen, which act to release the nitrogen from the descending liquid, carrying the nitrogen off through the pipes 91 and 91*, while the liquid containing oxygen and argon passes on down into the compartment 13. In addition, volatile gases are also admitted by the pipe 89 coming from the liquid-receiving chamber 49, which meets the spray and likewise separates the nitrogen from the descending liquid. The gases coming from pipe 89 are at a higher temperature and act to increase the separation which takes place in the separating chamber. The liquid which collects in the compartment 13 is rich in oxygen and argon. The liquid which collects in the compartment 13 is allowed to pass down through the condenser 29 through the spray 38, where it meets the ascending volatile gases, and in this case the argon, which is the more volatile gas, is separated, and passes around the condenser and through the pipe 33. The valve 28 is so regulated that the liquid in compartment 13 is maintained at a height to keep the coils in said compartment submerged. In its passage up through the condenser around the pipes 30, the argon, being of higher temperature than the liquid descending through the tubes, said liquid acts to condense any traces of oxygen which might remain in a gaseous state, and said oxygen liquefies and passes down into the compartment 16. In this way the liquefaction of all the oxygen is insured. The argon from the pipe 33 passes through the coil 34 and out through the pipe 35 down into the argon tank 36. The argon in its passage through the coil 34 cools the chamber 10 containing the incoming gases.

The liquid oxygen contained in the compartment 16 passes by the pipes 61 into the evaporators, where it is boiled by the action of the coils 64 and 65. The oxygen passes off by the pipes 66 and 67, uniting at 68, and passes by the pipes 69 into the coil 70, and by the pipe 71 to the oxygen tank 72. The oxygen in its passage through the coil 7 0 likewise acts to cool the incoming gases in the chamber 10. In this way the apparatus is capable of producing pure oxygen and pure argon by one operation.

I will now describe the operation of my improved apparatus in connection with the making of pure nitrogen at the same time that oxygen. and argon are being produced. In this case the air is admitted by the pipe 39 and forced by the compressor thr ugh the pipe 12, the valve 13 being open, and into the coil 4-2 in the cooling chamber 7. This air then passes out from the coil 4-2 by the pipe 44.- into the coil 45 in the cooling chamber 10. Thence it passes by the pipe 4-6 to the coil 16 in the lower compartment 13 of the upper separating chamber 14. From this coil 16 it passes by the pipe 4? down to the coil 47 in the lower compartment 16 of the separating char her 17 In its passage through the coils 46 and 47 in the chambers 13 and 16, the gas is partially condensed. From the. coil 47 the gas passes by the pipe 18, the valve 50 being open, to the liquid-receiving chamber 19. The liquid contained in chamber 49 passes by the pipe 51 down into the condensing chamber 23 to be discharged by the spray 2 1 into the upper compartment 25 of the upper separating chamber, where it is met by the rising gases which separate the more volatile ases in the manner herein described. At this point the valve 95 is opened and the valves 94 and 3 are closed, thus permitting the gas from the cooling chamber 10 to pass by the pipe 92 into the inlet pipe 2 to the compressor 4-. This gas, which has heretofore been passing through the pipe 92, and to the atmosphere by the pipe 93, was low in oxygen and rich in nitrogen. By shutting off the valve 94, opening the valve 95, and closing valve- 3, this gas is delivered to the compressor and is passed through the same course of piping as the gas originally brought from the atmosphere and compressed in the compressor 1. The gas, having passed throughthis piping system, is finally delivered by the outlet of the pipe 19 into the receiving chamber 20 in the form of liquid rich in nitrogen and the last traces of oxygen are liquefied and passed back to be again rectified in the chamber 25. The volatile constituents arising from the liquid rich in nitrogen in the chamber 20 pass off through the pipe 53 and enter the cooling chamber 7 to cool the incoming gases. The pipe 54 conducts this nitrogen gas oil through the pipe 56 to the atmosphere. This nitrogen at this stage may not be com mercia-lly pure, due to the fact that there may be a small percentage of oxygen which arises with the volatile nitrogen gases in the liquid chamber 20. In order to overcome this we pass off the volatile gas containing say 2% oxygen from chamber 20 by the pipe 96 back to the compressor 1, Where it is again compressed and liquefied, and this cycle is repeated until the pure nitrogen finally discharges through the pipe 56,

whereupon the valve 59 is closed and the valve '60 opened to discharge the pure nitrogen into the tank 58. To permit of the volatile gases passing off by pipe 96 it is necessary to partially close the valve 59 until pure nitrogen escapes from said valve, whereupon the valve 59 is closed and valve 60 opened to discharge the pure nitrogen into tank 58.

In the meantime the argon and oxygen are being produced in the manner previously described. In this way the apparatus is at one operation producing pure oxygen, argon and nitrogen.

Practically the only purpose of the compressor 74 is to force air into the pipe system connected up to the pipe 76, so as to supply air to boil oil the gases in the evaporators. A certain proportion of this gas is condensed in its passage through these coils and the liquid separated to be finally discharged into the liquid-receiving chamber a9. The volatile gases arising from liquid in chamber 49 pass by the pipe 88 down into the cooling chamber 80, where it acts to cool the gases passing through the coil 79. This gas is discharged by the pipe 89, and being heated, is delivered into the separator to assist in the separation of the liquid coming from the spray 2% into its constituents.

What I claim is:

1. In apparatus for the production of oxygen, argon and nitrogen, the combination of a chamber for containing liquefied air, a coil in said chamber, means for delivering compressed air to said coil, means for delivering liquefied air to said chamber,

a spraying device in said chamber whereby the nitrogen freed from said liquefied air in said chamber meets the liquefied air from said spray to free the nitrogen in the liquid air discharged from said spray, a. second chamber for liquefied air communicating with said first chamber, means for regulating the flow of liquid from said first chamber to said second chamber, a condenser in the path of the flow of the liquid from said first chamher to said second chamber whereby the argon is freed from said liquefied air, a spraying device below said condenser, and means for vaporizing the oxygen in said second chamber.

2. In apparatus for the separation of air the combination of a plurality of chambers adapted to receive liquid air from different sources of supply, a condensing chamber disposed below and adapted to receive liquid from both of the said liquid-receiving chambers, a spraying device disposed below the said condensing chamber, means for discharging, beneath the said spraying device, gaseous products from one of the said liquid-receiving chambers, a separating chamber disposed below the said spraying device, means for controlling the flow of liquid through the said separating cham bers, a condenser disposed below the said separating chamber, and a liquid receptacle disposed below the said condenser.

In testimony whereof, I the said JAMES G. LAFFERTY, havehereunto set my hand.

JAMES G. LAFFERTY. lVitnesses H. HEoK, Ron'r. D. To'rrnN. 

